File 0008-Appended-signature-verification.patch of Package qemu
From 157effb433b2c9630a1d27740f2eb79777cf8f36 Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Fri, 10 Apr 2020 01:24:56 +1000
Subject: [PATCH 08/12] Appended signature verification
Important Caveats!
* SLOF only rejects a binary if it's 32bit and _has the relevant
section_. It otherwise boots anything.
* There's no attempt to secure the OF prompt!
To use this:
- create certificate.der representing the public key used in signing
grub.
- xxd -i certificate.der > certificate.h, copy in over my certificate.h
- rebuild
- boot qemu with `-bios boot_rom.bin`
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
lib/libcrypto/Makefile | 12 +++-
lib/libcrypto/appended_sig.c | 102 ++++++++++++++++++++++++++++++
lib/libcrypto/certificate.h | 118 +++++++++++++++++++++++++++++++++++
lib/libcrypto/libcrypto.h | 5 ++
lib/libelf/Makefile | 3 +-
lib/libelf/elf32.c | 55 ++++------------
6 files changed, 249 insertions(+), 46 deletions(-)
create mode 100644 lib/libcrypto/appended_sig.c
create mode 100644 lib/libcrypto/certificate.h
create mode 100644 lib/libcrypto/libcrypto.h
diff --git a/roms/SLOF/lib/libcrypto/Makefile b/roms/SLOF/lib/libcrypto/Makefile
index e3c1231..c4df856 100644
--- a/roms/SLOF/lib/libcrypto/Makefile
+++ b/roms/SLOF/lib/libcrypto/Makefile
@@ -23,7 +23,17 @@ TARGET = ../libcrypto.a
all: $(TARGET)
-SRCS = mbedtls/library/sha256.c mbedtls/library/platform_util.c
+SRCS = appended_sig.c \
+ mbedtls/library/platform_util.c \
+ mbedtls/library/sha256.c mbedtls/library/sha512.c mbedtls/library/pkcs7.c \
+ mbedtls/library/asn1parse.c \
+ mbedtls/library/x509.c mbedtls/library/x509_crt.c mbedtls/library/x509_crl.c \
+ mbedtls/library/pk.c mbedtls/library/pk_wrap.c mbedtls/library/pkparse.c \
+ mbedtls/library/md.c mbedtls/library/md_wrap.c \
+ mbedtls/library/oid.c \
+ mbedtls/library/rsa.c mbedtls/library/rsa_internal.c \
+ mbedtls/library/bignum.c
+
OBJS = $(SRCS:%.c=%.o)
diff --git a/roms/SLOF/lib/libcrypto/appended_sig.c b/roms/SLOF/lib/libcrypto/appended_sig.c
new file mode 100644
index 0000000..4bebac2
--- /dev/null
+++ b/roms/SLOF/lib/libcrypto/appended_sig.c
@@ -0,0 +1,102 @@
+// appended_sig.c
+
+#include <libcrypto.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <mbedtls/pkcs7.h>
+#include "certificate.h"
+
+static char appsig_magic[] = "~Module signature appended~\n";
+
+struct module_signature {
+ uint8_t algo; /* Public-key crypto algorithm [0] */
+ uint8_t hash; /* Digest algorithm [0] */
+ uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */
+ uint8_t signer_len; /* Length of signer's name [0] */
+ uint8_t key_id_len; /* Length of key identifier [0] */
+ uint8_t __pad[3];
+ uint32_t sig_len; /* Length of signature data */
+};
+
+int verify_appended_signature(void *blob, size_t len) {
+ void *ptr;
+ mbedtls_pkcs7 *pkcs7;
+ mbedtls_x509_crt *x509;
+ int rc = 0;
+ struct module_signature *modsig;
+
+ // go to start of magic
+ ptr = blob + (len - sizeof(appsig_magic) + 1); // appsig_magic contains null-term
+
+ // again be careful not to require the null terminator
+ if (strncmp(ptr, appsig_magic, sizeof(appsig_magic) - 1)) {
+ printf("Appended signature: magic string missing. Aborting.\n");
+ return 0;
+ }
+
+ // now load the sig info
+ ptr -= sizeof(struct module_signature);
+ modsig = (struct module_signature *)ptr;
+
+ printf("%x %x %x %x %x\n", modsig->algo, modsig->hash, modsig->id_type, modsig->key_id_len, modsig->signer_len);
+ if (modsig->id_type != 2) { // pkcs7
+ printf("Appended signature: unexpected format (not PKCS#7). Aborting.\n");
+ return 0;
+ }
+
+ if (modsig->algo != 0 || modsig->hash != 0 || modsig->key_id_len != 0 || modsig->signer_len != 0) {
+ printf("Appended signature: unexpected parameter inconsistend with PKCS#7. Aborting.\n");
+ return 0;
+ }
+
+ // point at the pkcs7 data itself:
+ ptr -= modsig->sig_len;
+
+ // load into the pkcs7 code
+ pkcs7 = malloc(sizeof(mbedtls_pkcs7));
+ mbedtls_pkcs7_init(pkcs7);
+
+
+ rc = mbedtls_pkcs7_parse_der(ptr, modsig->sig_len, pkcs7);
+ if (rc) {
+ printf("Appended signature: error parsing PKCS#7 data: %d. Aborting.\n", rc);
+ rc = 0;
+ goto exit;
+ }
+
+ x509 = malloc(sizeof(mbedtls_x509_crt));
+ mbedtls_x509_crt_init(x509);
+ printf("%d\n", __LINE__);
+ rc = mbedtls_x509_crt_parse_der(x509, certificate_der, certificate_der_len);
+ if (rc) {
+ printf("%d\n", __LINE__);
+
+ printf("Appended signature: internal error parsing builtin x509 certificate. Aborting.\n");
+ rc = 0;
+ goto exit_x509;
+ }
+ printf("%d\n", __LINE__);
+
+ printf("ptr at %p, blob at %p, computed len %lu ? %lu\n", ptr, blob, len-(ptr-blob), (unsigned long)(ptr-blob));
+
+ rc = mbedtls_pkcs7_signed_data_verify(pkcs7, x509, blob, (ptr - blob));
+ if (rc) {
+ printf("%d\n", __LINE__);
+ printf("Appended signature: verification failed. Refusing to proceed.\n");
+ rc = 0;
+ goto exit_x509;
+ }
+ printf("%d\n", __LINE__);
+
+ rc = 1;
+
+exit_x509:
+ mbedtls_x509_crt_free(x509);
+ free(x509);
+
+exit:
+ mbedtls_pkcs7_free(pkcs7);
+ free(pkcs7);
+ return rc;
+}
diff --git a/roms/SLOF/lib/libcrypto/certificate.h b/roms/SLOF/lib/libcrypto/certificate.h
new file mode 100644
index 0000000..b48f1ee
--- /dev/null
+++ b/roms/SLOF/lib/libcrypto/certificate.h
@@ -0,0 +1,118 @@
+unsigned char certificate_der[] = {
+ 0x30, 0x82, 0x05, 0x55, 0x30, 0x82, 0x03, 0x3d, 0xa0, 0x03, 0x02, 0x01,
+ 0x02, 0x02, 0x14, 0x55, 0x50, 0x31, 0x0b, 0xf3, 0xea, 0xb8, 0xc9, 0xd6,
+ 0xac, 0x66, 0x80, 0x46, 0xa2, 0x00, 0x5a, 0x90, 0x47, 0x0e, 0x23, 0x30,
+ 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b,
+ 0x05, 0x00, 0x30, 0x34, 0x31, 0x32, 0x30, 0x30, 0x06, 0x03, 0x55, 0x04,
+ 0x03, 0x0c, 0x29, 0x47, 0x75, 0x65, 0x73, 0x74, 0x20, 0x53, 0x65, 0x63,
+ 0x75, 0x72, 0x65, 0x20, 0x42, 0x6f, 0x6f, 0x74, 0x20, 0x54, 0x65, 0x73,
+ 0x74, 0x20, 0x4d, 0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x53, 0x69, 0x67,
+ 0x6e, 0x69, 0x6e, 0x67, 0x20, 0x4b, 0x65, 0x79, 0x30, 0x20, 0x17, 0x0d,
+ 0x32, 0x30, 0x30, 0x31, 0x30, 0x37, 0x30, 0x36, 0x35, 0x32, 0x31, 0x37,
+ 0x5a, 0x18, 0x0f, 0x32, 0x31, 0x31, 0x39, 0x31, 0x32, 0x31, 0x34, 0x30,
+ 0x36, 0x35, 0x32, 0x31, 0x37, 0x5a, 0x30, 0x34, 0x31, 0x32, 0x30, 0x30,
+ 0x06, 0x03, 0x55, 0x04, 0x03, 0x0c, 0x29, 0x47, 0x75, 0x65, 0x73, 0x74,
+ 0x20, 0x53, 0x65, 0x63, 0x75, 0x72, 0x65, 0x20, 0x42, 0x6f, 0x6f, 0x74,
+ 0x20, 0x54, 0x65, 0x73, 0x74, 0x20, 0x4b, 0x65, 0x72, 0x6e, 0x65, 0x6c,
+ 0x20, 0x73, 0x69, 0x67, 0x6e, 0x69, 0x6e, 0x67, 0x20, 0x6b, 0x65, 0x79,
+ 0x30, 0x82, 0x02, 0x22, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
+ 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x82, 0x02, 0x0f, 0x00,
+ 0x30, 0x82, 0x02, 0x0a, 0x02, 0x82, 0x02, 0x01, 0x00, 0xd7, 0xf8, 0xeb,
+ 0x7c, 0x86, 0x6b, 0x7a, 0x06, 0x14, 0xd5, 0xa7, 0x76, 0x6b, 0xe3, 0xba,
+ 0xba, 0x57, 0x52, 0xe1, 0xfb, 0x1a, 0xd7, 0xd3, 0x65, 0xc2, 0x1f, 0x95,
+ 0x14, 0x67, 0x15, 0xc9, 0xa1, 0x61, 0x12, 0x59, 0xee, 0xd7, 0xdd, 0xa7,
+ 0xe3, 0x05, 0x4d, 0x5f, 0x99, 0xe5, 0xff, 0x89, 0xf9, 0x9f, 0x09, 0xa8,
+ 0x47, 0x76, 0x28, 0xbd, 0x3d, 0xb4, 0x04, 0x31, 0x13, 0xa5, 0x6f, 0x13,
+ 0x9d, 0x95, 0xc6, 0xd9, 0x3b, 0xa2, 0x60, 0x31, 0xf2, 0xe8, 0x22, 0xa0,
+ 0x7b, 0xc4, 0xdc, 0x36, 0x58, 0xdc, 0x69, 0xcb, 0xf1, 0xb6, 0x6f, 0x3a,
+ 0x90, 0x4e, 0xb8, 0x71, 0xf3, 0xfd, 0xee, 0x1a, 0x58, 0x74, 0x92, 0x3b,
+ 0x60, 0x73, 0x57, 0x36, 0xc3, 0x26, 0x61, 0x02, 0x29, 0xf3, 0xed, 0x0b,
+ 0xfe, 0xb5, 0x44, 0xc2, 0x02, 0x19, 0x32, 0x88, 0x8a, 0x58, 0x2c, 0x29,
+ 0x52, 0x59, 0xa0, 0xba, 0xce, 0xa2, 0xe8, 0xdd, 0xde, 0xbc, 0x5d, 0xc1,
+ 0x78, 0xcf, 0x53, 0x3b, 0xa5, 0x40, 0x95, 0x66, 0x0c, 0xed, 0xa6, 0x6a,
+ 0xb1, 0xab, 0x7c, 0xed, 0xbe, 0x0a, 0xf6, 0xc8, 0x44, 0x7d, 0x46, 0x1d,
+ 0x6e, 0xf2, 0xa6, 0xac, 0x91, 0x6e, 0x23, 0x82, 0x57, 0xc0, 0x96, 0x54,
+ 0xf6, 0xaa, 0x2c, 0x4c, 0x5f, 0xfc, 0xc7, 0xef, 0xaf, 0x06, 0x69, 0xff,
+ 0xf4, 0xb9, 0x3a, 0x73, 0x4a, 0xc4, 0x4d, 0x64, 0xe4, 0xb6, 0xd6, 0xae,
+ 0xd3, 0x3f, 0x04, 0x17, 0x30, 0xf1, 0xe8, 0x7e, 0x28, 0x61, 0xbc, 0xaf,
+ 0x38, 0x94, 0x99, 0x0a, 0xfd, 0x47, 0x74, 0x6a, 0xfd, 0x03, 0xaf, 0x13,
+ 0x88, 0x16, 0x74, 0xe0, 0x05, 0xe3, 0x33, 0x94, 0xd7, 0x8f, 0x67, 0xae,
+ 0xd6, 0xfe, 0xaf, 0xf2, 0x65, 0x9c, 0xd5, 0xb2, 0x64, 0x53, 0x58, 0x60,
+ 0x48, 0x75, 0x46, 0x67, 0x8b, 0x2b, 0xea, 0x59, 0x34, 0x57, 0xa6, 0x3f,
+ 0x90, 0xf1, 0xe9, 0x46, 0x08, 0xd1, 0xcd, 0xea, 0x8e, 0xf8, 0x6b, 0xc3,
+ 0xb8, 0xd3, 0x4c, 0x5a, 0x04, 0x5a, 0xae, 0xa6, 0x4a, 0x6e, 0xa9, 0xbc,
+ 0xe0, 0x03, 0x0f, 0x87, 0x17, 0x7d, 0xda, 0xb2, 0x61, 0x13, 0x23, 0x83,
+ 0x35, 0x01, 0xbb, 0x3c, 0x34, 0x63, 0x51, 0x3a, 0x99, 0x1d, 0x01, 0x18,
+ 0x01, 0xea, 0x39, 0x72, 0x84, 0x7d, 0x6e, 0x16, 0x93, 0xdc, 0x18, 0xa3,
+ 0x01, 0x97, 0x3a, 0x1b, 0x0b, 0xe3, 0x0d, 0x45, 0x68, 0x1f, 0xd4, 0xc6,
+ 0xf3, 0xbd, 0x62, 0xf2, 0xcf, 0xf4, 0x75, 0x14, 0x1d, 0x3c, 0x82, 0xff,
+ 0x34, 0x61, 0xa7, 0xa0, 0xcd, 0x9b, 0xa7, 0xa1, 0x7f, 0xc2, 0x2c, 0x44,
+ 0xd4, 0x3f, 0x8d, 0xe1, 0x49, 0x74, 0x17, 0xba, 0xab, 0x77, 0x7a, 0xa0,
+ 0x53, 0x62, 0x52, 0xa1, 0x57, 0xca, 0x74, 0xc1, 0x2b, 0x00, 0xad, 0x6f,
+ 0x3d, 0x85, 0xb4, 0xa3, 0x8a, 0xd2, 0x83, 0xd8, 0x1e, 0x30, 0xc1, 0x8d,
+ 0x8e, 0x16, 0xfc, 0x4b, 0xbe, 0xac, 0xeb, 0xd8, 0x02, 0x65, 0x61, 0x3c,
+ 0x90, 0x92, 0x41, 0xf4, 0xf9, 0xa4, 0xb3, 0x3a, 0xa5, 0x87, 0xdd, 0x71,
+ 0xe7, 0xf3, 0xd7, 0x54, 0xb7, 0x0c, 0x4a, 0xad, 0x0e, 0xe4, 0xa6, 0x94,
+ 0x2e, 0xef, 0x57, 0x56, 0xbc, 0x17, 0x70, 0x21, 0x11, 0xdb, 0x74, 0x0b,
+ 0x75, 0x75, 0x7d, 0x54, 0x32, 0xda, 0x2d, 0x5b, 0xc2, 0xfd, 0x3f, 0xbb,
+ 0x52, 0x63, 0x5e, 0xcc, 0x09, 0x99, 0x2b, 0x65, 0xe4, 0xce, 0xe8, 0xc7,
+ 0xd1, 0x93, 0xe3, 0x48, 0x66, 0x3b, 0x09, 0xfd, 0xc7, 0xa8, 0xdf, 0xd9,
+ 0xf9, 0x0d, 0xe4, 0x45, 0x23, 0x78, 0x99, 0x1e, 0xe9, 0x12, 0xed, 0x43,
+ 0x5f, 0xe8, 0x66, 0x25, 0x7a, 0x3d, 0x1b, 0x1b, 0x8c, 0xed, 0xd1, 0xbc,
+ 0x45, 0x0c, 0xb6, 0x47, 0x7b, 0xd7, 0x01, 0xda, 0x2d, 0xc3, 0x86, 0x70,
+ 0x0a, 0x79, 0x89, 0xc4, 0x21, 0x02, 0x03, 0x01, 0x00, 0x01, 0xa3, 0x5d,
+ 0x30, 0x5b, 0x30, 0x0c, 0x06, 0x03, 0x55, 0x1d, 0x13, 0x01, 0x01, 0xff,
+ 0x04, 0x02, 0x30, 0x00, 0x30, 0x0b, 0x06, 0x03, 0x55, 0x1d, 0x0f, 0x04,
+ 0x04, 0x03, 0x02, 0x07, 0x80, 0x30, 0x1d, 0x06, 0x03, 0x55, 0x1d, 0x0e,
+ 0x04, 0x16, 0x04, 0x14, 0x5e, 0x36, 0xba, 0x6f, 0x46, 0x13, 0xe2, 0x3c,
+ 0xc0, 0xc1, 0xfe, 0x77, 0x5e, 0x6a, 0x6a, 0xa8, 0x3f, 0x04, 0xc4, 0x05,
+ 0x30, 0x1f, 0x06, 0x03, 0x55, 0x1d, 0x23, 0x04, 0x18, 0x30, 0x16, 0x80,
+ 0x14, 0x45, 0xc3, 0x39, 0x5f, 0x3e, 0x5b, 0xcb, 0x0b, 0x21, 0x9a, 0xc2,
+ 0x4a, 0x3b, 0xea, 0xe2, 0x46, 0x73, 0xa2, 0x73, 0xd1, 0x30, 0x0d, 0x06,
+ 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00,
+ 0x03, 0x82, 0x02, 0x01, 0x00, 0xc0, 0x69, 0xc1, 0xba, 0x63, 0xe8, 0xb5,
+ 0xc7, 0xe2, 0x27, 0x7a, 0xe7, 0x78, 0xac, 0xfb, 0x49, 0xd4, 0x2b, 0xf7,
+ 0x19, 0x8e, 0x42, 0x2f, 0x0a, 0xd5, 0x17, 0x89, 0x02, 0xa4, 0x72, 0x5b,
+ 0x07, 0xe6, 0x87, 0x7c, 0xd6, 0x8e, 0x25, 0x1c, 0x9b, 0xf8, 0xca, 0x64,
+ 0xc7, 0xf2, 0xaf, 0x12, 0xd1, 0x51, 0xff, 0x5c, 0xe2, 0xe9, 0xd8, 0xb1,
+ 0xd4, 0x75, 0x60, 0xa9, 0x32, 0xac, 0xc0, 0x62, 0xc0, 0x36, 0xc3, 0xf2,
+ 0x4f, 0x1e, 0xb5, 0xe1, 0xce, 0x75, 0x76, 0x1c, 0x9e, 0xf9, 0x77, 0x30,
+ 0xd6, 0xa7, 0x5f, 0xe4, 0xf3, 0xb3, 0xbd, 0xbd, 0xe7, 0xde, 0xb8, 0xbf,
+ 0x3b, 0xf7, 0x39, 0x0b, 0xff, 0xc1, 0xa3, 0xb6, 0x44, 0x14, 0x50, 0xbe,
+ 0x46, 0xbe, 0xc4, 0xd2, 0xd3, 0xf1, 0xc6, 0x50, 0x56, 0x54, 0x99, 0x37,
+ 0x76, 0xd3, 0x21, 0x67, 0x48, 0x01, 0xce, 0x26, 0x9a, 0x3a, 0xb6, 0x89,
+ 0x9e, 0x22, 0xbd, 0x4a, 0x7a, 0x66, 0x0d, 0x49, 0xf0, 0xb9, 0xd8, 0xe1,
+ 0x02, 0x3a, 0x95, 0xe1, 0x63, 0x5e, 0x0a, 0xb4, 0x98, 0x9d, 0xf6, 0x14,
+ 0xb5, 0x8c, 0x05, 0x1d, 0x43, 0x32, 0x52, 0xbd, 0x92, 0x74, 0x45, 0x6e,
+ 0x92, 0xaa, 0xfd, 0x0f, 0xd0, 0x83, 0x14, 0x94, 0xd2, 0x87, 0x81, 0x9c,
+ 0x12, 0x8b, 0x6a, 0x84, 0xdd, 0x97, 0x10, 0x8b, 0xec, 0xc0, 0xf9, 0x00,
+ 0x3f, 0xd9, 0xb3, 0x0a, 0xb3, 0xf3, 0x6b, 0x1e, 0x0d, 0xd9, 0x10, 0xcb,
+ 0x71, 0x64, 0x47, 0x36, 0x21, 0xe3, 0x11, 0xf9, 0xe7, 0x8c, 0x5f, 0x4e,
+ 0x7f, 0x47, 0x1b, 0x6f, 0x80, 0x2b, 0xa5, 0x70, 0x3e, 0x19, 0xf8, 0x58,
+ 0x82, 0xe5, 0xb3, 0x79, 0xb4, 0x8d, 0x91, 0x68, 0x06, 0x43, 0x92, 0x82,
+ 0xf0, 0xfc, 0xa9, 0xe1, 0x03, 0x22, 0xa4, 0x46, 0x30, 0x9f, 0x44, 0xc8,
+ 0x1e, 0x73, 0xcb, 0x68, 0x41, 0xf2, 0xe8, 0x0a, 0x8a, 0xa2, 0x3c, 0x83,
+ 0xf0, 0xff, 0x8f, 0x7b, 0x7d, 0x7b, 0x4b, 0xe3, 0x6c, 0x11, 0x20, 0x7f,
+ 0xcd, 0xad, 0x23, 0x14, 0xf7, 0xee, 0x0a, 0x0e, 0x60, 0x76, 0x22, 0x33,
+ 0xf3, 0xa0, 0x97, 0xa2, 0xcd, 0x4e, 0xaa, 0xd1, 0x76, 0x34, 0x76, 0x02,
+ 0xda, 0xed, 0xa8, 0x3b, 0x08, 0xe8, 0x74, 0x03, 0x96, 0xdb, 0xdf, 0x9b,
+ 0x4f, 0xb2, 0x71, 0xde, 0xee, 0x4f, 0x34, 0xc5, 0xf1, 0x25, 0x89, 0xcb,
+ 0x6c, 0x99, 0x5a, 0xba, 0x32, 0x19, 0xc7, 0x23, 0xbc, 0xd3, 0xb3, 0xb2,
+ 0x0c, 0x49, 0x23, 0x01, 0x19, 0xba, 0x9c, 0x62, 0x0f, 0xc9, 0x3c, 0x5d,
+ 0xa7, 0x20, 0x89, 0xae, 0xa0, 0xa3, 0x1d, 0x91, 0x07, 0x16, 0x2a, 0xf9,
+ 0x08, 0xdb, 0xc6, 0xae, 0x94, 0x63, 0x6d, 0xbe, 0x6b, 0x72, 0x71, 0xb9,
+ 0xcc, 0xed, 0xbe, 0x97, 0xbd, 0x02, 0x24, 0x81, 0x1a, 0xe2, 0x59, 0xaa,
+ 0x7c, 0x23, 0x83, 0x64, 0x7c, 0x9a, 0x29, 0x1f, 0xfd, 0x34, 0xaa, 0xfe,
+ 0x9c, 0xa2, 0x3a, 0xaa, 0x2d, 0xe5, 0x13, 0x78, 0x06, 0xea, 0x5b, 0xd3,
+ 0x11, 0x35, 0x98, 0xe3, 0x2b, 0x2a, 0x26, 0x7e, 0x31, 0x2c, 0x06, 0xfe,
+ 0xe9, 0x79, 0x61, 0x0a, 0xab, 0x12, 0x56, 0x55, 0x53, 0xbd, 0xb5, 0xa8,
+ 0x6d, 0x7c, 0xaa, 0x52, 0x7b, 0xe8, 0x22, 0x1e, 0x8e, 0x3c, 0xb9, 0x92,
+ 0x92, 0xbb, 0xc8, 0x70, 0x85, 0xba, 0xd5, 0xb4, 0x33, 0xcd, 0x0f, 0x7f,
+ 0x76, 0xc8, 0x6f, 0x13, 0x64, 0xf2, 0x7a, 0xcd, 0x82, 0x41, 0x8e, 0xec,
+ 0x0e, 0x43, 0xa9, 0x19, 0x79, 0x9f, 0x59, 0x9e, 0xf0, 0xb3, 0x50, 0x85,
+ 0x94, 0x22, 0x95, 0x4b, 0xf6, 0x5c, 0xb7, 0xf3, 0xbe, 0x66, 0xfa, 0x3f,
+ 0x75, 0x84, 0x07, 0x3c, 0x97, 0x71, 0x9f, 0x43, 0x71, 0xd1, 0x50, 0xfa,
+ 0x75, 0xd0, 0x59, 0x1e, 0xb1, 0xd0, 0x2d, 0xd3, 0x8d, 0x16, 0x5c, 0xdf,
+ 0x61
+};
+unsigned int certificate_der_len = 1369;
diff --git a/roms/SLOF/lib/libcrypto/libcrypto.h b/roms/SLOF/lib/libcrypto/libcrypto.h
new file mode 100644
index 0000000..2980ca0
--- /dev/null
+++ b/roms/SLOF/lib/libcrypto/libcrypto.h
@@ -0,0 +1,5 @@
+// libcrypto.h
+
+#include <stddef.h>
+
+int verify_appended_signature(void *blob, size_t len);
\ No newline at end of file
diff --git a/roms/SLOF/lib/libelf/Makefile b/roms/SLOF/lib/libelf/Makefile
index 34a8f20..ce43457 100644
--- a/roms/SLOF/lib/libelf/Makefile
+++ b/roms/SLOF/lib/libelf/Makefile
@@ -14,7 +14,8 @@ TOPCMNDIR ?= ../..
include $(TOPCMNDIR)/make.rules
-CPPFLAGS = -I../libc/include $(CPUARCHDEF) -I$(INCLCMNDIR) -I$(INCLCMNDIR)/$(CPUARCH)
+CPPFLAGS = -I../libc/include $(CPUARCHDEF) -I$(INCLCMNDIR) -I$(INCLCMNDIR)/$(CPUARCH) \
+ -I$(LIBCMNDIR)/libcrypto
LDFLAGS= -nostdlib
TARGET = ../libelf.a
diff --git a/roms/SLOF/lib/libelf/elf32.c b/roms/SLOF/lib/libelf/elf32.c
index f378db0..6896e64 100644
--- a/roms/SLOF/lib/libelf/elf32.c
+++ b/roms/SLOF/lib/libelf/elf32.c
@@ -18,11 +18,10 @@
#include <libelf.h>
#include <byteorder.h>
#include <helpers.h>
+#include <libcrypto.h>
#define ALIGN(x, a) (((x) + ((a) - 1)) & ~((a) - 1))
-static char appsig_magic[] = "~Module signature appended~\n";
-
struct ehdr32 {
uint32_t ei_ident;
uint8_t ei_class;
@@ -74,16 +73,6 @@ struct nhdr32 {
uint32_t n_type;
};
-struct module_signature {
- uint8_t algo; /* Public-key crypto algorithm [0] */
- uint8_t hash; /* Digest algorithm [0] */
- uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */
- uint8_t signer_len; /* Length of signer's name [0] */
- uint8_t key_id_len; /* Length of key identifier [0] */
- uint8_t __pad[3];
- uint32_t sig_len; /* Length of signature data */
-};
-
static struct phdr32*
get_phdr32(void *file_addr)
{
@@ -145,8 +134,7 @@ elf_load_segments32(void *file_addr, signed long offset,
post_load);
} else if (phdr->p_type == PT_NOTE) {
struct nhdr32 *nhdr = (struct nhdr32 *)(file_addr + phdr->p_offset);
- char *ptr;
- struct module_signature *modsig;
+ size_t size;
//printf("%x %x %x\n", nhdr->n_namesz, nhdr->n_descsz, nhdr->n_type);
// todo - endiansafeness
@@ -154,39 +142,18 @@ elf_load_segments32(void *file_addr, signed long offset,
if (nhdr->n_type == APPENDED_SIGNATURE_NOTE_TYPE) {
// todo, verify name
- // check for magic
- // go to start of appsig block
- ptr = (char *)(nhdr) + sizeof(struct nhdr32) + ALIGN(nhdr->n_namesz, 4);
- // go to start of sig
- ptr += nhdr->n_descsz - sizeof(appsig_magic) + 1; // appsig_magic contains null-term
-
- if (strncmp(ptr, appsig_magic, sizeof(appsig_magic))) {
- printf("ELF32: appended signature note present but magic string missing. Aborting.\n");
- return 0;
- }
-
- // now load the sig info
- ptr -= sizeof(struct module_signature);
- modsig = (struct module_signature *)ptr;
-
- //printf("%x %x %x %x %x\n", modsig->algo, modsig->hash, modsig->id_type, modsig->key_id_len, modsig->signer_len);
- if (modsig->id_type != 2) { // pkcs7
- printf("ELF32: appended signature is in an unexpected format (not PKCS#7). Aborting.\n");
- return 0;
- }
-
- if (modsig->algo != 0 || modsig->hash != 0 || modsig->key_id_len != 0 || modsig->signer_len != 0) {
- printf("ELF32: appended signature has an unexpected parameter inconsistend with PKCS#7. Aborting.\n");
- return 0;
- }
-
+ // not clear if this is of value or how to still do it.
//printf("%u %u %u -1 = %u\n", modsig->sig_len, sizeof(struct module_signature), sizeof(appsig_magic), nhdr->n_descsz);
- if (ALIGN(modsig->sig_len + sizeof(struct module_signature) + sizeof(appsig_magic) - 1, 4) != nhdr->n_descsz) {
- printf("ELF32: Appended signature component sizes don't add up as expected. Aborting.\n");
+ /*if (ALIGN(modsig->sig_len + sizeof(struct module_signature) + sizeof(appsig_magic) - 1, 4) != nhdr->n_descsz) {
+ printf("ELF32: Appended signature: component sizes don't add up as expected. Aborting.\n");
+ return 0;
+ }*/
+ size = (phdr->p_offset + sizeof(struct nhdr32)
+ + ALIGN(nhdr->n_namesz, 4)
+ + ALIGN(nhdr->n_descsz, 4));
+ if (!verify_appended_signature(file_addr, size)) {
return 0;
}
-
-
}
}
/* step to next header */
--
2.33.1
